233.170.  County commissions may form districts. — 1.  County commissions of counties not under township organization may divide the territory of their respective counties into road districts, and every such district organized according to the provisions of sections 233.170 to 233.315 shall be a body corporate and possess the usual powers of a public corporation for public purposes, and shall be known and styled "______ road district of ______ County", and in that name shall be capable of suing and being sued, of holding such real estate and personal property as may at any time be either donated to or purchased by it in accordance with the provisions of sections 233.170 to 233.315, or of which it may be rightfully possessed at the time of the passage of sections 233.170 to 233.315, and of contracting and being contracted with as herein provided.

  2.  Districts so organized may be of any dimensions that may be deemed necessary or advisable, except that every district shall be included wholly within the county organizing it and shall contain at least six hundred and forty acres of contiguous territory; provided, that the county commissions shall not have power to divide the territory within the corporate limits of a city having a population of one hundred fifty thousand into such road district.